The present invention is directed to an enossal single tooth implant, which is provided with a twisting restaint to enable a firm seating of a tooth replacement.
Enossal implants have been described in U.S. Pat. No. 4,793,808, whose disclosure is incorporated herein by reference thereto, and which claims priority from the same German Application as European Published Application 0 216 031. The implants disclosed in this Patent have proven satisfactory. However, a difficulty may occur when the implant is used as a single tooth implant because it is not possible to reliably prevent the tooth replacement from twisting or turning relative to a base body, unless the individual parts of the implant and the tooth replacement are bonded together. If these two parts are bonded together, difficulties may occur in the case of a subsequent replacement for either the tooth replacement or the implant post, if either fails due to breakage.
U.S. Pat. No. 5,026,285, whose disclosure is incorporated herein by reference thereto, and which claims priority from German Application P 39 17 690 discloses an enossal individual tooth implant and locking tool for use with the implant. This implant includes a base body which is implanted in the jaw bone and has a threaded bore for receiving a threaded member or base element of a spacer ring, which has an upper ring element or spacer bushing top for spacing an implant post from the base body. The base element has a bore for receiving the post for mounting the tooth replacement. In order to obtain a twisting restraint, the spacer bushing top or ring element of the pre-assembled base single tooth implant, according to U.S. Pat. No. 5,026,285, is constructed in a ring nut-like manner and can be threaded onto the base element by means of an interlocking thread with a much smaller pitch than the set thread of the spacer bushing bottom or base element, which are received in the base body. The base body and the spacer formed by the bushing top and the spacer bushing bottom can be locked and braced with one another, which leads to a twisting restraint of both the spacer bushing bottom receiving the implant post and the spacer bushing top. However, it does have the disadvantage, in certain uses, in that, in the case of locking with a special tool, the spacer bushing top and bottom must be secured against any relative rotation or twisting. Problems are sometimes encountered in operating such a special tool, particularly when the operator is relatively inexperienced.